Although matlab GUI is simple, we may still need multiple windows in one app. How to access data of another window is a problem. I searched a lot and encountered this post,

This post shows a simple yet efficient way to do so. However, not perfect. The code will activate the other window when acquiring the handle of window (put it on the top). So, I suggest a way. Let’s use parent window and child window to describe the two window according to which one opens the other.  Thus, one can keep the child window’s handle in the parent window at the first time of open child window, and at the same time, put parent window’s handle inside the child window so that the child window can access the parent window.

Here, I don’t show the code because I haven’t tried. Anyone tested could send me an example. I will put it here